The present invention relates in general to lifting devices and pertains, more particularly to hand cranked vertical support systems utilizing gear means to provide mechanical advantage in lifting furniture systems (e.g., modular office systems that could include walls and furniture). The adjustable lifting apparatus of this invention provides an improvement over the conventional support systems used to raise office partitions.
The present invention is characterized by first gear means for converting rotary motion into linear motion, second gear means for transmitting motion and power between the first gear means and a shaft located at a right angle to the first gear means, enclosing means, supporting means, and connecting means including interchangeable fittings which are capable of being attached to an object to be lifted.
With the conventional support systems, which typically utilize a crowbar like tool, it is generally necessary to continually lift and then lower, and then move the tool and lift again when installing carpeting either by the yard or in tiles. The same drawback occurs when removing carpeting, tile, or other type or styles of flooring. As the size of the project increases a drawback associated with conventional methods and devices occurs due to the time it takes to complete the project.
Since existing methods and tools for installing flooring generally require the removal of a substantial amount of furniture, a business may have to either shut down during the project to have the furniture, partitions, file cabinets and the like moved twice, once to clear an area for removal and replacing and again to replace the furniture. Another drawback that occurs relates to the additional costs that are not related to the actual flooring project.
Known devices include a moveable fulcrum pin for adjusting the height of a lever supported by a stand or an upright frame supported on a base block, or a base member with outwardly extending wings, or a plurality of vertical standards supported by a base member. Prior devices are used in automobile jacks, window lifting devices, and lifting devices in general. The existing jacks and jacking devices also have a drawback in that they provide a jack that is not particularly suited or adaptable to uses other than those for which the jack is intended.